Conveyors



Aug. 13, 19.63 M. M. LEVY 3,100,564

CONVEYORS Filed Nov. 17, 1961 United States Patent O 3,100,564 CONVEYORS Maurice M. Levy, 20S Clemow Ave.,

Ottawa, Ontario, Canada Filed Nov. 17, 1961, Ser. No. 153,127 3 Claims. (Cl. 198-165) er which reads each set of code markings and determines from information stored in a le computer to which sortation outlet the letter or card in question should be conveyed. A compartment is provided y'at each `outlet to receive the letters or cards diverted thereto and to form these letters `or cards into a stack yfor subsequent handling. A plurality `of such outlets is provided, to any one of `which the system may selectively convey each letter, card or like dat 4ax-ticle (hereinafter referred `to simply as articles).

When the number of such outlets becomes large, it is convenient` to use both spans of la conveyor. Instead of arranging all the outlets along the outgoing span of the conveyor, the return span is also employed, thus halving the total length of the conveyor for a given number of outlets. Such an arrangement, however, involves reversing the direction of travel of many of the articles at the end of the conveyor, `and this requirement has given rise to diiiiculties, especially as conveyor speeds have increased. The centrifugal forces exerted on the articles can become considerable.

The problem of making sure that the articles do not become detached from the conveyor Ias they turn the corner from the outgoing to the return span, without placing undesirable restrictions on conveyor` speed, has been tackled in the past only by employ-ing firmer and more powerful grippers to secure the yarticles to the conveyor. Not only does this expedient have the disadvantage of adding considerably to the complexity `of construction of the lgrippers, but it fails to protect the articles against bending or tearing in those not positively held by the grippers. Normally such a gripper mere-ly engages an edge of the article-usually the leading edge to pull the article along, although some systems use pusher elements. In either case, little `or no real control is exercised on the parts of the yarticles not positively gripped, and no provision is made to restrain the generally disruptive eliects of the centrifugal forces.

The object of the present invention is to provide an improved conveyor structure that will overcome these difficulties in a convenient and reliable manner.

'I'his object is satisfied by the present invention by the provision of an auxiliary conveyor that extends adjacent to and equidistant from the main conveyor along the convex side of that portion of the main conveyor where the change of direction takes place. This [auxiliary conveyor includes article-supporting means that project into engagement with an article on the main conveyor to support it against displacement due to centrifugal forces. 'Ihe travel of the two conveyorsl will be coordinated, to cause such article-supporting means to travel synchronously with the article throughout the curved portion of the main conveyor.

The preferred form that the article-supporting means take is at least one set of individual lingers that project from the auxiliary conveyor towards the main conveyor.

3 ,l00,54 Patented Aug. 13, r1963 Each set will conveniently include a plurality of spaced rows of fingers whereby to distribute the support over a substantial area `of the surface of each flat article.

A further desirable feature of the finger construction is that the length of such fingers should be graded from front to rear `on the conveyor so as to supply substantially equal support over the length of a hat article which projects tangentially from the main conveyor while travelling around the curved portion thereof.

These and other features `of the invention will appear more Aclearly from the example illustrated in the accompanying drawings `and described below.

In such drawings:

FIGURE l is a plan view lof a conveyor end, modified in accordance with the invention; and

FIGURE 2 is la fragmentary side perspective of FIG- URE l.

The main conveyor 10 of a sorter `or other larticle handling machine extends around a drum 11, which may be driven by power means not shown, or may be an idling drum, in which case the drum at the liar end of the conveyor will be driven. At regularly spaced intervals, the conveyor 10 is provided with `grippers l2 tor gripping the leading edges of letters 13 to carry them` along the conveyor. The specific construction of such grippers forms no part of the present invention and consequently will not be described in detail; suffice to `say that such grippers include jaws capable of being `opened to receive a letter at a loading lstation at the far end `of the conveyor (not shown) Iand to deposit the letter at any selected `one :of a series `of receiving stations distributed along both spans of the conveyor. i

While travelling along the straight spans lof 4the conveyor the letters are yadditionally suppor-ted. -on tracks 14. These tracks terminate just short of the drum 11 where their function is yassumed by three support ledges 15 mounted on the lower part o-f the drum to project tangentially therefrom at three positions Ispaced equally around the drum.

An auxiliary conveyor 16 is mounted on idler rollers 17 in the shape of a crescent extending adjacent the convex side of the curved portion of the main conveyor 10 which travels 'around the drum 11. The span of the auxiliary conveyor 16 which is adjacent the main conveyor is arranged to be equidistant therefrom throughout the yfull length of the curved portion of the main conveyor. The auxiliary conveyor 16 extends at its ends around drums 18 and 19, the d rum 18 being driven through drive 20 from drum 11 in order to synchronise the movements of the tvyo conveyors. The conveyor 16 consists of a rubber bel-t provided with ra plurality Iof sets of firm but resilient projecting, article-supporting lingers 2l. As best seen in FIGURE 2 each such set of lingers 21 comprises a top row 21u to engage a letter 13 near its upper edge anda bottom row 2lb to engage the letter near its lower edge. The lengths of the lingers in each row are graded from long at the front (in the direction of conveyor travel) to shorter at the rear, so as to supporta letter substantially equally along its length while it projects tangentially Ifrom the curved portion of the main conveyor 10. This is clearly shown ein FIGURE l. The angular speeds of the conveyors are made equal and the positioning of the sets of fingers 21 is so arranged that each letter, as it enters the turn, finds a set of lingers waiting to support i-t, `and to travel with it, the full distance around the curved portion.

`As will be appreciated, the specic arrangement of the article-supporting lingers, as to positioning and relative length, may be varied as necessary to suit the requirements of `any particular main conveyor. For ins-tance, if the conveyor employs pusher elements that engage the rear edges of the articles, instead of the pulling `grippers illustrated, so that the articles will travel around the turn of the conveyor with their leading rather than trailing edges. projecting from .the conveyor and requiring support, the shorter fingers will require to -be in 'front of the longer fingers on the auxiliary conveyor.

The change of direction of travelV need not necessarily' take the form of an 180 turn, although this will be the most common example encountered.l The invention is equally applicable to turns of a conveyor through any angle. 'Moreoven theV arc through which the conveyor turns need not necessarily be a circular arc. What is essential is that the Iauxiliary conveyor should lrnove in a similar arc, so as always to be'equidistant from the curved portion of the conveyor. In other Words, the two conveyors arcs will lat any :given angular position always be described about a common instantaneous centre, and their angular rather than their linear speeds will be equal.

I claim:

1. The combination of (a) a main conveyor for flat articles, said conveyor 'having la portion at which the direction of travel of the conveyor is turned through a semi-circular arc,

and said conveyor having mea-ns for conveying said articles in such a manner that -said articles project tangentially from the convex side of said conveyor While travelling around said portion,

(b) and lan auxiliary conveyor havin-g la substantially semi-circulrarly extending span described about a conimon centre with the yarcuate portion of the main conveyor, whereby to extend adjacent to and equidistant from said portion on the convex side thereof, said auxiliary conveyor including (i) a plurality of sets of article-supporting lingers projecting from the surface of said auxiliary conveyor into engagement withfa said article on the main conveyor to support t-he same against displacement due tocentrifugal forces, the fingers of reach said set being graded in length in the longitudinal direction of the auxiliary conveyor so as to supply substantially equal support over the length of a said article while projecting tangentially as aforesaid,

(ii) and `means for coordinating the travel of said 4 conveyors to bring a said set of fingers into supporting engagement with an article as it enters the arcuate por-tionand to cause said set to travel synchronously with said article throughout the full extent of said portion.

2. The combination of claim 1, wherein said arcuate portion of the main conveyor extends' around a drum, -said drurn Abeing provided with a plurality of ledge-s each projecting tangentially lfrom a lower portion of the drum and arranged to provide additional support for a said article traversing the arcuate portion of the conveyor.

3. The combination of (a) a main conveyor for flat articles, said conveyor having a portion over which a change of direction of travel takes place with the result that `said portion has a convex side,

(b) and an auxiliary conveyor having a span extending adjacent to and equidistant from said main conveyor along the convex side of said por-tion, said lauxiliary conveyor including (i) article-supporting means projecting into en'- Igagernent with a flat article on said main conveyor to support the same against displacement due to centrifugal forces,

(ii) and means coordinating the travel of said conveyors to cause said article-supporting means to travel synchronously with -said article throughout said portion,

(iii) said article-supporting means comprising at least one set Vof individual fingers that project `from the side of the auxiliary conveyor towards References Cited in the le of this patent FOREIGN PATENTS 73,584 Netherlands Nov. 16V, 1953 

1. THE COMBINATION OF (A) A MAIN CONVEYOR FOR FLAT ARTICLES, SAID CONVEYOR HAVING A PORTION AT WHICH THE DIRECTION OF TRAVEL OF THE CONVEYOR IS TURNED THROUGH A SEMI-CIRCULAR ARC, AND SAID CONVEYOR HAVING MEANS FOR CONVEYING SAID ARTICLES IN SUCH A MANNER THAT SAID ARTICLES PROJECT TANGENTIALLY FROM THE CONVEX SIDE OF SAID CONVEYOR WHILE TRAVELLING AROUND SAID PORTION, (B) AND AN AUXILIARY CONVEYOR HAVING A SUBSTANTIALLY SEMI-CIRCULARLY EXTENDING SPAN DESCRIBED ABOUT A COMMON CENTRE WITH THE ARCUATE PORTION OF THE MAIN CONVEYOR, WHEREBY TO EXTEND ADJACENT TO AND EQUIDISTANT FROM SAID PORTION ON THE CONVEX SIDE THEREOF, SAID AUXILIARY CONVEYOR INCLUDING (I) A PLURALITY OF SETS OF ARTICLE-SUPPORTING FINGERS PROJECTING FROM THE SURFACE OF SAID AUXILIARY CONVEYOR INTO ENGAGEMENT WITH A SAID ARTICLE ON THE MAIN CONVEYOR TO SUPPORT THE SAME AGAINST DISPLACEMENT DUE TO CENTRIFUGAL FORCES, THE FINGERS OF EACH SAID SET BEING GRADED IN LENGTH IN THE LONGITUDINAL DIRECTION OF THE AUXILIARY CONVEYOR SO AS TO SUPPLY SUBSTANTIALLY EQUAL SUPPORT OVER THE LENGTH OF A SAID ARTICLE WHILE PROJECTING TANGENTIALLY AS AFORESAID, (II) AND MEANS FOR COORDINATING THE TRAVEL OF SAID CONVEYORS TO BRING A SAID SET OF FINGERS INTO SUPPORTING ENGAGEMENT WITH AN ARTICLE AS IT ENTERS THE ARCUATE PORTION AND TO CAUSE SAID SET TO TRAVEL SYNCHRONOUSLY WITH SAID ARTICLE THROUGHOUT THE FULL EXTENT OF SAID PORTION. 